泥炭记录的帕米尔高原晚全新世温度变化研究

近年来,“全新世温度谜题”已经受到全球古气候学者的广泛关注,为了解决这一谜题,需要在全球不同区域进行更多的全新世温度重建。帕米尔高原位于亚洲内陆核心区域,目前有关帕米尔高原全新世气候变化的研究相对较少,且已有的研究主要集中于相对湿度(或降水)变化的研究,而涉及温度变化的成果则相对较少。论文首先研究了表土碳同位素与气候因子之间的相关关系,结果显示帕米尔高原的δ¹³C_org与温度正相关;进一步在7个AMS ¹⁴C测年数据的支持之下,基于175个泥炭δ¹³C_α-cellulose分析,重建了帕米尔高原过去约5000 a的温度变化历史。结果发现：帕米尔高原晚全新世以来整体呈现波动升温趋势,约5000~3600 cal a BP阶段处于缓慢降温期;约3600~200 cal a BP处于波动升温期;驱动机制分析显示,约3600 cal a BP之前温度下降主要是夏季太阳辐射下降导致的,约3600 cal a BP之后温度上升是由温室气体辐射强迫增强导致的。

Peat δ13Cα-cellulose-based late Holocene temperature reconstruction in Pamir,China

In recent years, "Holocene temperature conundrum" has received extensive attention from paleoclimatologists. In order to solve this conundrum, more Holocene temperature reconstruction needs to be carried out in different regions of the world. The Pamir region of Xinjiang, China, is located in the core area of inland Asia and many scholars have conducted in-depth studies on the Holocene climate change in this region. However, these studies are mainly focused on precipitation (or humidity) rather than temperature. In this study, the correlation between topsoil carbon isotopes and climatic factors (temperature and precipitation) was first established, and the results showed that δ¹³C_org in Pamir was highly positively correlated with temperature. Supported by the AMS ¹⁴C dating data of seven samples and 175 peat δ¹³C_α-cellulose data, the temperature variation in Pamir during the past ~5000 year was reconstructed. Generally, Pamir has shown a warming climate during late Holocene and the change can be further divided into two sub-stages: a fluctuating cool period from ~5000 cal a BP to ~3600 cal a BP and a fluctuating warming period since ~3600 cal a BP. The driving mechanism analysis shows that the temperature decrease before ~3600 cal a BP was mainly controlled by the decrease of summer solar radiation and the temperature increase since ~3600 cal a BP was mainly controlled by the enhanced radiative forcing of greenhouse gases and human activity.